78126017 has 2 divisors, whose sum is σ = 78126018. Its totient is φ = 78126016.

The previous prime is 78125977. The next prime is 78126019. The reversal of 78126017 is 71062187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69739201 + 8386816 = 8351^2 + 2896^2 .

It is a cyclic number.

It is not a de Polignac number, because 78126017 - 2²² = 73931713 is a prime.

It is a super-2 number, since 2×78126017² = 12207349064568578, which contains 22 as substring.

Together with 78126019, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_4566515 and since 78126017 and 4566515 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (78126019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39063008 + 39063009.

It is an arithmetic number, because the mean of its divisors is an integer number (39063009).

Almost surely, 2^78126017 is an apocalyptic number.

It is an amenable number.

78126017 is a deficient number, since it is larger than the sum of its proper divisors (1).

78126017 is an equidigital number, since it uses as much as digits as its factorization.

78126017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4704, while the sum is 32.

The square root of 78126017 is about 8838.8922948523. The cubic root of 78126017 is about 427.4958416430.

The spelling of 78126017 in words is "seventy-eight million, one hundred twenty-six thousand, seventeen".